One of the legal education reforms that I have advocated is explicitly teaching miniskills, such as rule-based reasoning, analogical reasoning, and case synthesis. I think that students need to master these skills before moving on to more advanced types of legal reasoning. Studies have shown that second- and third-year law students have problems with these and other miniskills. (E.g., here)

One miniskill that is rarely taught in depth in law school is distinguishing cases. Yet, this skill is basic for competent lawyers.

A lawyer can distinguish a case based on the facts or based on the reasoning/policy (or preferably both).

In distinguishing cases, the attorney demonstrates that the facts of case A (the precedent case) are not substantially similar to the facts of case B (your case) so that the rule from case A does not apply to case B. In other words, distinguishing cases is the opposite of reasoning by analogy. With reasoning by analogy, the advocate shows that the facts of case A (the precedent case) are substantially similar to the facts of case B (your case) so that the rule of case A applies to case B.

Distinguishing cases involves distinctions of degree so the lawyer must make the dissimilarities convincing. The opposing attorney will try to argue that the cases are similar enough for the rules to apply to both.

Judge Aldisert has developed criteria to test analogies:

* The acceptability of the analogy varies proportionally with the number of correlates that have been identified.

* The acceptability of the analogy depends on the number of positive resembles (similarities) and negative resemblances (dissimilarities).

* The acceptability of the analogy is influenced by the relevance of the purported analogies. An argument based on a single relevant analogy with a single instance will be more cogent than one which points out a dozen irrelevant resemblances. (Ruggero J. Aldisert, Winning on Appeal: Better Briefs and Oral Argument 280 (Nat. Instit. Trial Advoc. 1996))

This test can be modified to apply to distinguishing cases: in making an attempt to distinguish a case convincing, find as many relevant distinguishing features as possible and compare the relevant differences with the relevant similarities.

An advocate can also distinguish cases based on the reasoning or policy of the cases. Case A (the precedent case) is distinguishable from case B because the policy (or the reasoning) behind case A is different than the policy (or the reasoning) of case B so the rule from case A does not apply to case B.